The mechanistic origin of amber pigmentation of Perithemis tenera (Say, 1840) wings (Odonata: Libellulidae) and its function in conspecific signalling.

Animal coloration serves various signaling and non-signaling functions. In damselflies and dragonflies (Odonata), such colors may not only play photoprotective and/or thermoregulatory roles but also serve as visual signals during courtship and/or agonistic interactions. Here, we analyzed the coloration of Perithemis tenera wings, a potential secondary sexual ornament, applying spectrophotometry and visual modeling to gain a deeper understanding of their color mechanisms and functions.

A meta-analysis on alternative mating tactics: when the main and the alternative yield similar reproductive success.

In many species, individuals of the same sex exhibit different mating behaviours, a phenomenon known as alternative mating tactics (AMTs). These AMTs may occur in species in which morphology prevents individuals from adopting different tactics (fixed expression of AMTs) as well as in species in which individuals can alternate between them (flexible expression of AMTs). Regardless of the way different mating tactics are expressed, a key point to understanding the selective forces driving AMT evolution relies on identifying differences in the reproductive success between tactics.

The hidden links between animal weapons, fighting style, and their effect on contest success: a meta-analysis.

In many species that fight over resources, individuals use specialized structures to gain a mechanical advantage over their rivals during contests (i.e. weapons).

What do we need to know to recognize a contest?

Animals frequently use agonistic contests as a way to solve disputes over indivisible resources. Such agonistic contests often represent interactions between an owner and a non-owner of a resource. However, some behaviors adopted by rivals during agonistic interactions are similar to behaviors adopted in other types of interactions.

All by myself? Meta-analysis of animal contests shows stronger support for self than for mutual assessment models.

Since the 1970's, models based on evolutionary game theory, such as war of attrition (WOA), energetic war of attrition (E-WOA), cumulative assessment model (CAM) and sequential assessment model (SAM), have been widely applied to understand how animals settle contests. Despite the important theoretical advances provided by these models, empirical evidence indicates that rules adopted by animals to settle contests vary among species. This stimulated recent discussions about the generality and applicability of models of contest.

Decreasing water availability across the globe improves the effectiveness of protective ant-plant mutualisms: a meta-analysis.

Abiotic conditions can increase the costs of services and/or the benefits of rewards provided by mutualistic partners. Consequently, in some situations, the outcome of mutualisms can move from beneficial to detrimental for at least one partner. In the case of protective mutualisms between ant bodyguards and plants bearing extrafloral nectaries (EFNs), plants from arid environments face a trade-off between EFN production and maintenance and water and carbon economy.

Drivers of Spatial Variation in the Role of Ants as Secondary Seed Dispersers.

The spatial variation in the outcome of the interaction between secondary dispersers and seeds is superimposed upon the variation produced by primary dispersers. Investigating the factors that drive the outcome of the interactions with secondary seed dispersers thus represents an essential refinement to our understanding of the complete seed dispersal process. We studied the interactions between two ponerine ants (Pachycondyla striata Smith, 1858 and Odontomachus chelifer (Latreille, 1802)) with fruits experimentally set on the ground, and estimated the effects of ants on seedling establishment in three areas distributed along a 2-km stretch of a Brazilian Atlantic rainforest that differ in soil properties and vegetation physiognomies.

Do morphological and physiological characteristics of males of the dragonfly Macrothemis imitans determine the winner of territorial contests?

Males of many animal species show intraspecific disputes for mating territories that range from displays without physical contact to physical fights with risk of injury. This variation motivated the proposition of different models that suggest possible rules used by rivals to decide the contest winner. To evaluate those models, it is necessary to identify how males behave during the fight and the individual attributes that determine their fighting ability (resource holding potential).

Do territorial butterflies show a macroecological fighting pattern in response to environmental stability?

The territorial defense of mating sites by males should be favored when female monopolization is possible. Such monopolization should occur in species in which females emerge asynchronously, since males may have time to copulate with one female before the arrival of other. However, regions with smaller reproductive windows should promote higher synchronicity of female emergence, generating a predictable macroecological pattern associated to the rewards from territorial defense.

No size or density effect on alternative mate-locating tactics in the tropical damselfly Hetaerina rosea males (Odonata: Calopterygidae).

Males of the damselfly Hetaerina rosea may defend mating sites along river margins (resident males) or, alternatively, wander among different areas presumably searching for mates (nonterritorial males). Although the occurrence of territorial and nonterritorial males of H. rosea is very common in Brazil, studies examining which factors may be responsible for the adoption of alternative mate-locating tactics in this species are inexistent.